The Environmental Protection Agency is finalizing its draft rule to set new limits on power plant carbon pollution. Even though we served in dramatically different administrations, we strongly agree that carbon emissions must be reduced and the use of low-carbon energy sources increased. We believe using carbon-free energy sources is the first step towards solving the climate change challenge and moving our nation toward a clean-energy future.

Laws passed by Congress with bipartisan support encourage clean energy technologies and are helping reduce air pollution. Today, proposed EPA regulations strike a balance between reaching significant carbon reduction goals and providing states with the flexibility to achieve them. Flexibility does not mean lowering goals; rather it recognizes different states have different challenges and potential solutions to reduce carbon pollution.

As a Republican and a Democrat, we do not always see eye-to-eye on public policy, and there are areas within EPA’s proposal where we don’t necessarily agree. However, we strongly agree that America should better utilize its clean energy portfolio -- wind, solar, efficiency and existing nuclear power facilities -- to combat climate change.

As we work to reduce carbon emissions, we can't ignore any existing carbon-free source of energy. Nuclear energy produces nearly two-thirds of all carbon-free electricity to American homes and businesses. Internationally recognized leaders in the energy and environmental field from the United Nation’s Intergovernmental Panel on Climate Change to the Clean Air Task Force have recognized nuclear power to be part of a clean energy portfolio that along with renewables and energy efficiency programs reduces carbon pollution.

States will have the opportunity to implement EPA’s new standards and will have the flexibility to develop customized plans to reduce carbon pollution. Properly crediting a state’s current level of carbon-free energy from nuclear energy is an important step in the EPA rulemaking. Doing so will encourage states to work to keep today’s clean-air energy facilities in operation at what is an important turning point in energy and environmental policy.

We are hopeful that a strong rule that credits all emission-free sources of energy will further encourage business and federal leaders to accelerate development of clean-air energy sources that will move America into a cleaner future and slow the impacts of climate change.

Climate change is one of the most important issues affecting the health and well-being of future generations. As U.S. and global policymakers consider steps toward cleaner energy portfolios, they must recognize the importance of a diverse energy portfolio.

Carol Browner, former Environmental Protection Agency administrator, is a member of the leadership council of Nuclear Matters, a campaign to raise awareness about the need to preserve existing nuclear energy plants.

Christine Todd Whitman, former Environmental Protection Agency administrator, is co-chair of the Clean and Safe Energy Coalition, a national grassroots organization that works to advance the national dialogue about our energy options and the value nuclear energy provides to America’s economy and the environment.